remote-info: Fix --show-metadata behavior

When the --show-metadata option is used with remote-info, the metadata
variable is never initialized, causing flatpak to print "(null)". This
commit makes sure the variable is properly initialized so the metadata
prints correctly.

Closes: #1313
Approved by: alexlarsson
This commit is contained in:
Internal Server Error - Gitea: Git with a cup of tea
500 Internal Server Error

Gitea Version: 1.28.0+dev-477-g8b6ad49a5f